One of the most important changes in the U.S. healthcare system in the past thirty years is the increased dissemination of data on health care quality at the health plan, hospital and physician level. There have been special challenges in measuring quality at the physician level. The largest and most comprehensive physician quality reporting effort in the U.S. is Medicare's Physician Quality Reporting Initiative or PQRI, begun in mid- 2007. This proposed research will use interrupted time series analyses to examine the relationship between the PQRI quality measures and four different outcome measures: avoidable emergency department (ED) visits, ambulatory care sensitive (ACS) hospitalizations, readmissions, and health expenditures. The analysis will be based on large Medicare claims data bases (including PQRI reports) covering the years 2000 to 2010, to address the following questions: 1. Is there a relationship between the PQRI measures and the outcome measures in cross-sectional data? 2. Was the onset of PQRI reporting associated with a favorable change in measures of health outcomes? 3. Was the frequency of PQRI reporting associated with a favorable change in measures of health outcomes? 4. Do these results vary according to the race, ethnicity, or sex of the patient? Do they vary by type of chronic illness? In addition, this project will interview selected physicians and CMS managers to explore the implementation and operation of the PQRI process, in order to suggest ways to improve the PQRI process? PQRI constitutes the nation's largest data collection effort on health care quality at the individual provider level. This proposed research is the first study designed to test whether this large effort has had an effect on health outcomes and expenditures. PUBLIC HEALTH RELEVANCE: One of the most important developments in the U.S. health care system has been the collection of data on quality of care. Medicare's Physician Quality Reporting Initiative (PQRI) is the nation's largest data collection effort on health care quality from individual providers. To understand if this quality reporting makes a difference, this study will analyze relationships among physician reporting, quality outcomes, and expenditures, with special attention to whether results vary according to the race, ethnicity, or sex of the patient, or by type of chronic disease diagnosis.